1. Field of the Invention
The present invention relates generally to a warning system and method that provides a warning to people in the vicinity of the device that an action is occurring or will occur. Particularly, the present invention relates to an aerialift warning system and method that provides a warning to people in the vicinity of the device that an action is occurring or will occur. More particularly, the present invention relates to an aerialift warning system and method that provides a warning to an aerialift operator to attach the safety lanyard and to people standing or walking within the vicinity of an aerialift boom/basket attached to a truck used for performing maintenance on pole cabling, sign repair, and the like.
2. Description of the Prior Art
Aerialift booms are mechanical conveyances mounted on a parked and stationary vehicle which permit persons to be lifted in a basket vertically from an initial ground position for the purpose of performing maintenance on pole cabling, sign repair, and the like. Several problems associated with the use of aerialift booms are accidents that occur when the aerialift operator fails to fasten his lanyard to the aerialift boom/basket and when aerialift booms/baskets are moving. Aerialift operators have suffered serious injuries caused by falls from the aerialift basket when working suspended above the ground because they have forgotten to attach their safety lanyards. Others below a suspended aerialift boom/basket have been seriously injured when the suspended aerialift boom/basket moves downward.
Descending aerialift booms and baskets are hazardous to traffic control personnel and/or law enforcement officers who are often times present around the aerialift vehicle while work is being performed on electrical, telephone, CATV, or fire alarm systems. It is also hazardous to other employees and/or pedestrians who wander under and around the ground area surrounding the aerialift device. Much of the time an aerialift boom operator is working above the ground, he/she is naturally blinded to individuals below who wander beneath the aerialift boom. These potential accident victims have a threat attention space which is generally focused horizontally as a matter of natural tendencies, and as such these individuals are unaware of potential life-threatening dangers posed by the aerialift boom and/or aerialift basket.
The horizontal and vertical deployment of the aerialift presents special problems in protecting individuals under this device, since the range of danger associated with the aerialift boom basket can be quite large in both the horizontal and vertical directions. Typical deployment envelopes for aerialift devices have deployment ranges with vertical heights of 30 feet and horizontal deployment distances of 25 feet. This large deployment range means that any device used to warn individuals of the danger presented by the aerialift device must have characteristics different than conventional backup warning devices to be effective in this application, since the range of danger is much larger than for a conventional piece of construction equipment or the like.
Various prior art warning devices have been designed specifically for limited purposes. Signaling devices on vehicles to indicate that they are in a backward motion are well known in the art. Other devices have been designed for use as an audible warning for bicycles. However, the aerialift vehicle in most instances is parked and stationery with chock blocks on the rear wheels to assure that the vehicle remains in a secure, fixed position while the aerialift operator works aloft. There is no known prior art that solves the problems associated with injuries occurring from descending aerialift baskets or objects falling from these baskets.
U.S. Pat. No. 3,818,438 (1974, Stacha) teaches a tamper-proof backup electrical warning system for use on heavy vehicles. The device provides an audible signal to warn persons standing to the rear of a vehicle of backward movement of the vehicle. The electrical warning system has two flasher units and two signal circuits that can be selectively operated by a manual switch.
Several aspects of this invention make it inappropriate for use in aerialift applications. In the context of many aerialift applications, there exists the distinct possibility that many ground-based commercial vehicles will be moving in close proximity to the aerialift device. The problem here is that the Stacha device or a variant of it has been mandated by the Occupational Safety and Health Administration (OSHA) for use on most commercial vehicles. Thus, if an aerialift warning device used the same warning mechanism to indicate vertical threats, it is possible that this audible warning would be drowned out by the audible warnings of other commercial vehicles. This confusion could result in desensitization to the danger associated with the vertical aerialift threat.
U.S. Pat. No. 4,013,996 (1977, Hubbard) teaches a safety device which causes the signal indicator lights of a vehicle to flash on and off when the vehicle is being backed, thus providing a warning to pedestrians and other members of the driving public in the vicinity.
The problem with the Hubbard device as applied to aerialift applications is that unless the aerialift is operated at night, this warning is ineffectual to provide adequate notice to persons below the aerialift boom that there is an impending danger from above when the aerialift descends. In fact, during periods of bright sunlight, the Hubbard device would be ineffectual at providing any notice that there was an impending danger. The signal lights of the aerialift vehicle would in many cases be washed out by the bright ambient sunlight.
U.S. Pat. No. 5,132,665 (1992, Hutchisson et al.) teaches a self-powered backup alarm which is mounted to the wheel hub of a heavy truck or like vehicle. The alarm of this device is activated on the movement of the wheel hub when the truck moves in a backwards direction. The self-powered nature of the invention is useful in situations where a retrofit of the electrical wiring system to affect the functionality of the Hubbard invention would be prohibited. The Hutchisson device is not directly applicable to the aerialift application, because there is no moving wheel mechanism which would provide an activation means for the Hutchisson alarm. Furthermore, since the vehicle from which the aerialift boom is deployed is stationary, the triggering means required for the Hutchisson device is lacking in this instance.
U.S. Pat. No. 5,262,757 (1993, Hansen) teaches an electronic audible warning device which includes a power source, a motion detector, a pleasant tone generator, a loud piercing tone generator, and a remote push button activated switch. The signaling device provides two distinct features, each in response to remote activation by manual switch. A single depression on the remote push-button switch will sound a pleasant two second pulsating warning tone. Two consecutive depressions of the remote push-button switch will sound an attention-getting pulsating signal similar to the backup beeper on commercial trucks. The motion detector portion of the Hansen device is limited in scope to use as an anti-theft, anti-tampering device for the bicycle to which the alarm is attached.
As with previous patents, the Hansen device requires manual triggering of the alarm function. Key to the Hansen implementation is the fact that this alarm is designed to be placed in the front of a bicycle and triggered when the operator is aware of a potential accident victim. This scenario differs significantly from that of the aerialift application in which the operator may have no knowledge of a potential victim beneath the aerialift basket. In short, the Hansen device as well as the other prior art provides no means of providing warning in cases where the aerialift operator is unaware of the potential accident victim.
U.S. Pat. No. Des. 336,864 (1993, Gottlieb) describes a backup warning signal lamp fixture. This design patent does not disclose any functional features which might be applicable to the special needs of aerialift warning devices.
Therefore, what is needed is a warning device that provides an audible warning to individuals standing in proximity to an aerialift boom/basket when the basket is descending or moving in a vertical direction. What is further needed is a warning device that produces an audible warning which provides a specific indicia of the vertical nature of the danger present in proximity to the aerialift boom/basket and which is distinguishable from other OSHA-style backup warnings currently used within the construction industry. What is still further needed is a warning device that produces an audible warning which provides a specific indicia of the danger associated with a descending aerialift boom/basket and which provides a audible warning to individuals standing in proximity to an aerialift boom/basket when the basket is moving. What is yet further needed is a warning device that permits the use of multilingual safety messages (English, Spanish, French, etc.) to be emitted by a warning device which targets the zone of danger associated with the aerialift boom device. What is yet further needed is a warning device that reminds the aerialift operator to attach his/her safety lanyard to the boom/bucket.